Air cylinder



AIR CYLINDER 7 she ts-sheet 1 Filed March 1, 1944 w aw T. 0 Y W mw k IS 1 F a @wh v .4, i mm m I 6 w 16 A v H1 11 m mm 4mm ww g mu H mm fifimm Jan. 3L 1950 w. F. SCHROEDER 2,495,859

AIR CYLINDER Filed March 1, 1944 I '7 Sheets-Sheet 2 I INVENTOR. ZfldllczmFJo/zrqeder Jan; 811, 1950 w. F. SCHROEDER AIR CYLINDER 7 Sheets-Sheet 5 Filed. March 1, 1944 INVENTOR. M'Zliam FJc/z feeder Wig,

Jam. 31, 1950 w. F. SCHROEDER 2,495,369

AIR CYLINDER FiledMamh 1,; 11944 I 7ShQets-Sheet 4 Jan. 31, 1950 w. F. SCHROEDER 2,495,869

AIR CYLINDER Filed March 1, 1944 '7 Sheets-Sheet 5 Jane 31, 1950 w. F. SCHROEDER 2,495,869

AIR CYLINDER Filed March 1, 1944 7 Sheets-Sheet 7 INVENTOR. I "iii ZflllamFSc/zwoedew Patented jan. 31 19 5( UNITED STATES PATENT OFFICE 4 Claims.

The invention herein disclosed and described is directed to an improved construction of air cylinder or air operated unit in combination with the Operating parts of a standard chuck or a collet chuck so as to place one or the other of the latter in active work or tool holding relation; or to release either at predetermined intervals as the case may be. The air cylinder may be adapted to various purposes for numerous functions, but in order to best describe its use and operation in a workable set up, the same has been more specifically applied to operate the clamping jaws of a conventional collet chuck for the purpose of holding a piece of work at certain intervals to be acted or worked upon in any known manner in a lathe, automatic screw machine or in any typ of metal working machine or instrument. In addition, the air cylinder is so arranged and designed as to be particularly applicable for use in connection with a collet chuck of a metal working machine wherein the stock maybe axially fed or introduced into the collet chuck'without affecting the operation or power efficiency of the air cylinder, the feeding of the stock being unobstructed and unimpaired by the cylinder installation.

With the more general adaptations of the air cylinder given above, some of the main objects of the present air cylinder unit shall be'better understood. One of the main objects is to, provide a fluid operated mechanism that will cooperate between the rotatable collet parts and the supporting rotatable spindle of the lathe or machine which carries and drives the collet chuck; and wherein such fluid operated mechanism is entirely devoid of fluid seals such as packings, mechanical leakproof accessories, stufiing boxes or like fluid retainers ordinarily utilized to prevent fluid loss between relatively rotating parts and possible pressure drop that may introduce work slippage of the stock within the collet while being worked upon. The maintenance and replacements of such fluid seals has always been a problem, and the only answer to eliminate inefiiciency, breakdowns and delays due to the impractical life and faults of such seals is to eliminate using the same. And this has been accomplished with the air cylinder of the present invention.

Obviously, any packing or glands operating between two relatively moving parts are always subjected to considerable wear and the faster the relative speeds of the parts the greater the wear. The generation of heat in such glands or packings further shortens the useful life and efficiency of such fluid seals.

With the air cylinder of the present invention which actually in its primary conception amounts to an annular expansible diaphragm cyl nder, attention is called to the fact that the cylinder and its operating parts are held against rotation and out of contact with the rotatable parts of a metal working machine. This manner of installation is directly contra to the usual air cylinders on the market which do rotate and require the use of various devices or mechanical methods of introducing air from a stationary source into a rotatable cylinder. Naturally these units for feeding air and the cylinders must further incorporate various glands, packings or stufiing boxes or the like to prevent air leakage at the various points of air transfer between relatively moving parts of such assemblies.

Therefore, another main object of this invention is to provide an air cylinder that is stationary with respect to the spindle and collet parts to thereby eliminate all forms of glands or other complicated small tolerance fluid transfer means to introduce fluid from a stationary source to a revolving cylinder mechanism or the like. The disadvantages and corresponding impractical arrangements that must be resorted to in valving or feeding fluid from a stationary source into a revolving unit, or vice versa are self-evident. Such arrangements include devices comparatively costly to manufacture on the basis of the short time that such devices actually remain efiicient due to surface wear or to burning out or scoring because of frictionally produced heat.

Further, this design has for an additional object the provision of an air cylinder for the purposes set forth which is actually entirely independent of the rotatable members of the lathe or metal working machine. This resides in the fact that the cylinder is suspended from suitable supporting units and is centrally'open to provide more than enough clearance to be substantially axially aligned with the lathe spindle working axis but at the same time spaced annularly out of contact with the spindle and its companion moving parts, referrin to the collet chuck parts, etc.

Another object of this air unit is to provide certain anti-friction mechanisms so arranged as to be interposed between the stationary air cylinder and the rotating spindle and collet chuck operating draw tube, respectively, to reduce rotational friction between the relatively movable members to a minimum while in operation.

Various other features are also incorporated in certain disclosed and described modifications of the preferred form of device to demonstrate the flexibility of use and application of the fundamental principles embodied in the air cylinder unit of this invention. Such modifications together with further advantages and merits of the air cylinder will hereinafter be emphasized in the following detailed description directed to the disclosures in the accompanying drawings.

In the drawings:

Fig. 1 is a general side elevational view of the stock feeding end of a lathe to illustrate a preferred manner of installation of the preferred form of air cylinder, certain parts being broken away and in section to show the spindle and collet chuck details;

Fig. 2 is a sectional face view of the cylinder in Fig. 1 as taken substantially along the line lf-Z in Fig. 1

Fig. 3 is an axial sectional view through the air cylinder as viewed substantially along the line 3 3 in Fig. 2;

Fig. 4 is a view, similar to Fig. 2, of a modified form of air cylinder shown in elevation;

Fig. 5 is a side view of the air cylinder of Fig. 4, part of which is in section as taken substantially along the line 5-5 of Fig. 4;

Fig. 6 is an elevational face view of another modified construction of air cylinder, also viewed from the stock feed end of the lathe as are Figs. 2 and .3, and substantially. along the line 676 of Fig. 7;

Fig. 7 is a fragmentary sectional view of the modification in Fig. 6 as taken along the line '.''i in Fig. 6;

Figs. 8 and 9 are sectional viewsas taken along the line 8-3 and 9- 9, respectively, in Fig. 6, to illustrate certain details of construction;

Fig. 10 is a modified arrangement for the sus; pension of the air cylinders in floating relation to the rotatable lathe members:

Fig. 11 illustrates a face View of still. another embodiment of air cylinder of a double acting construction;

Fig. 12 is a sectional viewof'the Fig. 11 cylinder as taken substantially along the line Il-Tll in Fig. 12; and

Figs. 13 and 14 are sectionaldetails toillustrate certain additional substitutionalconstructions that may be utilized in carrying out theprinciples of this invention to accomplish the result desired.

Referring now to Figs. 1, 2 and 3 showing the preferred construction of air. cylinder l5, such cylinder is preferably supported orv suspended substantially in coaxial relationship to the spindle .i

l5 of a lathe I! and the, draw tube I 8 of'a collet chuck 26. Spindle I6 is supported forrotation in bearings 2i and 22 in the lathe. head 23, and held against axial movement by the flange 24 and appropriate means such as a collar25secured thereto. Collet 20 is of a conventional design having work holding jaws 26 coacting-with the conical internal surface 21 of the collet ring--28, The stock or work 30 is fed by appropriate equip:v ment from the left in Fig. 1, between the collet jaws 26 up against a work stop such as 3|. The collet jaws 26 are moved axially by means of a collet tube 32 having an annular flange 33,001,1-

in Fig. 1. end 34 within the spindle l6 at 35.

Referring to Fig. 3, the end of the spindle i6. is.

threaded to receive a threaded bearing-collar 36 which may be in the form of a. nut WhiCI'LiSr internally bored at 3! to slidablyreceive and Cil support the end 38 of the draw tube l8 of the collet 2U. Collar supports a thrust bearing 40 upon the reduced end 4| and a cupped abutment housing 42 is mounted on the bearing 40 and coacts with collar 36 to protect and house bearing 40. The structure including collar 36, bearing 4| and housing 42 all constitute the anti-friction means, indicated by 43, which is directly mounted upon the end of the rotatable spindle l6.

Similar anti-friction means 44 is connected with the terminal end 38 of the draw tube l8 and disposed in spaced relation to the anti-friction means 43. Means 44 comprises a flanged supporting ring 45 and a cupped collar 46 confining and supporting the thrust ball bearing 41 therebetween, said ring and collar being held together by the locking ring 48 through screws 49 as clearly illustrated in Fig. 3. A nut 39 is threaded upon the end of the draw tube l8 to hold the bearing 44 in place upon said tube.

The expansible assembly comprising the air cylinder l5, see Figs. 1 and 3, is interposed between the two anti-friction means or units 43 and 44 and is supported in floating relation to the spindle l6 and draw tube l8 in pendulum fashion to permit axial movement of the air cylinder parts or transverse movement thereof as the case may be. The air cylinder I5 can be supported in any number of ways, but, as shown in Fig. l, a bracket 50 in the form of a plate is suitably bolted to the lathe head 23 and has projections 5i and 52 ex.-v tending outwardly to adjustably receive the brackets 53 and 54, see Figs. 1 and 2. Brackets 53 and 54 carry stub rods 55 and 56, respectively, to pivotallysupport pairs of links 57-51 and 58-7-53, respectively. Links 51-51 are pivotally connected with stub ins 60 and GI secured to opposite parts of the air cylinder [5, while links 58-58' connect with similar pins one of which shows at 62 in Fig. 2.

The entire suspension of the air cylinder l5 as just described permits self-alignment of the cyl-v inder unit within the space between the two anti: friction bearings 43 and 44 axially of the spindledraw tube assembly through the looseness of the links with their connected parts, and transverse movement is also possible because of the pivotal connectionsof the link ends in the manner shown in Figs. 1, 2 and 3,

The air cylinder I5 comprises chiefly two annular plates or discs 64 and 65 having an annular ia ra m heli tw en an arran ed to m he a sa e und r flu su ei phr m- 66 is secured to plate 64 at its outer periphery by means of a rin 61 through screws 68, while the central open; portionof the diaphragm is similarly ecur 9. la 6 b me n o n It and the screws H, see Figs. 2 and 3, Plate 64 may be considered as the diaphragm plate and has. an annular recess I2 in the face thereof to form an, air receiving cavity that may besupplied with fluid under pressure through asuitable pipe line- 13. Plate 64 has an axial opening 14 aligned with the diaphragm opening and the inner peripheral. V edge of ring 10 of such a size as to provide adequate clearance between the air cylinder unit l5 and the external circumference of draw tube [8 to avoid all frictional contact therebetween.

Plate 65 of the air cylinder I5 acts in the capacity of a follower having an annular protuberance 15 on the face thereof adjacent the diaphragm 66 and also has a relatively large central opening 76 therein to clear rin 10 and also draw tube l8. The protuberance 15 on plate 65 and the recess 12 in plate 64- together coact With the 5 diaphragm 66 to permit greater axial separation between the plates under the action of fluid pressure from pipe 13. A plurality of spring units 11, as in Figs. 2 and 3, provide a means for moving plates or discs 64 and 65 together and; to thereby collapse the diaphragm into the position shown in Fig. 3. Each spring unit is made toreplace one of the screws 68 and comprises an internally threaded pin I8 which tightens upon;the end of a screw 88 and against ring 61, pin 'I8jfltting through an opening 8| in plate 65 while a spring 82 is confined between the secured washer 8.3 on the pin I8 and the plate 65. Thus springs 82 act to normally hold the plates 64 and 65.1% shown in Fig. 3' or urge them into this position when separated by the diaphragm.

When-the air cylinder parts are in the position shown in Figs.-1 and 3, the draw tube I8 is given the necessary freedom and play to releasejlthe collet jaws 26 and to permit freedom of passage of the stock 38 axially between the jaws 26. l-Iowever, when air is introduced through pipe ISj IltO recess I2, the diaphragm will tend to invertitself to move plates 64 and 65 apart. Under thesconditions, plate 64 reacts against the anti-friction unit 43 and obviously against spindle I6 while plate 65 reacts against the anti-friction means 44 carried upon the collet draw tube I8. Since the spindle I6 and its associated bearing 43 do not move axially, the bearing 44 and draw tube I8 are urged outwardly away from the cylinder 'end of the spindle to cause the collet jaws 26 tomove radially inwardly to grasp and hold the stock 38 which may then be worked upon in the customary manner to produce fabricated articles therefrom.

Referring now to Figs. 4 and 5, the principles of the invention have been embodied in a modified arrangement of air cylinder unit 85 to obtain greater collet gripping power with the same line fluid pressures. Here the device incorporates a multiple construction having a plurality of units similar to the Fig. 3 air cylinder and indicated in Fig. 5 by 86, 87 and 88, respectively. Each unit has a diaphragm plate 98, diaphragm 9| and follower plates 82, and fluid under pressure is introduced through a pipe line 93, and branches 84 into each of the units 86, 87 and 88 in the manner shown in Fig. 5.

In this construction the plates 98 are all secured together and in axially aligned relationship by the bolts 95 and spacer bushings 96,'and plate 98 of unit 86 abuts the face of bearing 43 of the spindle I6. Each of the plates 92 is connected with spacing sleeves 91 slidably supported in the central openings 98 in the diaphragm plates 98. Therefore, with the bolts 95 and spacers 96 holding the plates 98 and with the latter slidably carrying the sleeves 91 and the follower plates 92, the sleeve openings indicated at I88 are maintained in aligned relationship for the purpose of providing sufflcient clearance between the fluid power means or air cylinder 85 and the draw tube I8.

By introducing fluid through pipe 93, the total surface pressure of the diaphragm 9| will act collectively through the follower plates 92 and their bushings 9's to move the bearing 44 and its connected draw tube I8 to the left in Fig. 5. This multiple unit is provided with brackets I82 secured by longer bolts I8I, similar to bolts 95, so as to confine springs I83 between the brackets and the plate 92 of unit 88 for the purpose of returning the cylinder parts to normal position when rendered inactive. The reaction of springs I83 upon the face of plate 92 In unit 88 is transmitted to the other follower plates 82 through the sleeves 91 as is clearly apparent from Fig. 5.

This multiple power unit 85 is also suspended from the lathe or other support adjacent thereto 5 by links I84--I04 and I85--I85 as best illustrated in Figs. 4 and 5.

With the above described construction greater force is transmitted to the draw tube although the total possible movement of the tube is substantially the same as the air cylinder in Figs. 1, 2 and 3.

Referring now to Figs. 6, 7, 8 and 9, another modified construction is disclosed also embodying the same general principles of the air cylinder in the first form but so arranged as to be in multiple succession as in the Fig. 5 construction with the exception that the units are made to act in series to obtain greater movement of the draw tube I8 relative to the spindle I6.

In this construction as best illustrated in Fig. 7, III) represents one plate which carries a diaphragm III and has a sleeve II2 secured centrally thereto encircling the draw tube I8. Plate II8 abuts bearing 43 on spindle I 8. Another plate II3 acts as the follower in this case abutting bearing 44 and having sleeve II4 secured to the central opening therein to slidably telescope into sleeve I I2 to keep the cylinder parts in a1ignment when being actuated relatively to each other during operation. Intermediate plates H5 and H6 are sandwiched between plates H8 and I I3 and each of the former act as both diaphragm and follower plates carrying the diaphragms I I1 and II 8 respectively. The intermediate plates H5 and H6 ride on sleeve II2 whereby all the plates are kept in axial alignment and the telescoping sleeves are of such internal diameters as to clear draw tube I8 as shown in Fig. '7.

Individual flexible fluid tubes I28, I2! and I22 40 supply air or other fluid into the annular cylinder chambers I23, I24, and I25 of plates H8, H5 and I I6, respectively, and preferably from the same power source to equalize the separation between adjacent plates. The Fig. 7 unit may be suspended in any suitable manner, but one preferred way is illustrated in Figs. 6 and 7. Plate II8 remains in its position during operation so pins I26 are connected therewith and an adjustable hook link I2'I can be hooked over rods or 80 shafts I28 carried in brackets I38 secured to the lathe head 23 and the links are provided with an eye I3I to slip over a pin I26.

Plate II 3 is provided with pins I32 each to be engaged by a hanger I33 carrying an overhead 55 wheel I34 to ride upon rods I28 with the movement of the leading plate II3, see Figs, 6 and '7.

The multiple series operated air unit is therefore suspended in floating relation to the draw tube I8 and the parts of such unit are free to separate and come together during the operation of the device. In the latter construction of air cylinder the parts are urged into inoperative nested relation by means of a plurality of spring assemblies such as indicated by I35 in Figs. 6 and 8. Brackets I36 and I31 are secured to plates 8 and H3, respectively, with threaded studs I33 secured to brackets I31 for slidably projecting through sleeves I48 carried by brackets I36. Springs I4I 70 are interposed between brackets I36 encircling sleeves I48 and the spring holder I42 adjustably carried upon pins I38 by the fastening nuts I43.

With this arrangement the pressure upon the nestedplates can be varied to suit conditions.

78 In Fig. 100. modified construction of carrier is ua-see disclosed Ifor supporting an air 'cylinderin spaced relation axially with respect to the draw tube. Here brackets such as I are connected to the front and back plates to adjustably carry wheel's I46 for horizontal adjustment. Also, rods or shafts I41 are adjustably carried'by brackets I48 fastened to the lathe head 23 for vertically positioning rods I41. With these vertically and horizontally adjustable means and the wheel and rod combination, movement is .permitted by the air cylinder plates and the form of suspensionallows prepositioning of the cylinder with respect to the draw tube I8.

Figs; 11 and 1-2 portray the use of an air cyline der having means for actuating, the collet draw tube in either direction axially ofthe. machine. The construction is for the purpose of positively moving the tube into colletljaw releasing position for freeing the stock and for quick action as a means for eliminating the spring return feature connected with the previously described air cylinders. Very quick release of the work or stock is desirable when higher speed production'is sought and also under certain other conditions of operation.

In this arrangement the outer end of the draw tube I8 is journalled in a bushing I58 in spindle I6 and projects outwardly therefrom. Ashoulder I51 is provided on the tube to back up bearing I52 while nut 39 is used to position bearing I53 in spaced relation to bearing I52 as shown in Fig. 12. In this construction the bearings I52 and I53 are analogous to bearings 43 and 44 of the other forms with the exception that they are here shown as interchangeable for reasons well apparent to those skilled in the art.

The fluid operated air cylinder in this construction embodies a pair of diaphragm plates I54 and I55 having diaphragms I56 and I51 secured thereto respectively. shouldered bolts- I58 are used'to secure plates I54 and I55'together and in alignment and one or more brackets I80 connected with the lathe are fastened to plate I54 to provide the supporting means therefor and to position the air unit withrespect to draw tube I8 and the bearings I52 and I53. Disposed between diaphragms I56 and I51 is an annular follower plate I6I having a central sleeve I62 as a part thereof which surrounds the draw tube I8 and also is slidably supported in the openings I53 and I64 in plates I54 and I55 respectively. The opposite ends of sleeve I62 are adapted to abut bearings I52 and IE3 to actuate the draw tube when the diaphragms impart motion to plate IBI. The bulbous cross-sectional contour of plate I6I is for obtaining greater movement under the nested diaphragm arrangement'with the recessed plates I54 and I55 in the sameman ner as previously described in the Fig. 3 form.

The fluid under pressure is here supplied from its source through pipe I65 to a valve I56 and the latter diverts air through one or the other of the pipe lines I51 or I68 to either chamber I18 or III. This will cause actuation of the collet tube" in either direction to make the collet hold the work or release the same as the casemay be.

In the hereinbefore described structures the diaphragm construction and the manner of securing the same has been substantially uniform and has proven satisfactory. Figs. 13 and 14:

have been added to suggest modified diaphragms:

In Fig. 13 the diaphragm I12 is made up-as a bellows having annular flexible rings I13 and I14 suitably joinedat I15 and fastened at I16 and- I11 to the plates I18- and I80. A secondset of g annular flexible rings I81 and PH -ire ioinediit I83, and are also'secured at I84 and I85 to'iplatei I18 and I80. Thus an annular air cylinder is provided having the enclosed chamber I88 between plates I18 anal-so.

In the Fig. 13 constructionapair of telescoping sleeves I81 and I88 are carried by lplates I18 and I to keep the same aligned duringopera-tion. The entire unit may be bodily suspended in any manner as taught by the other embodiments described and disclosed, and the unit-is inter-' posed between interchangeable bearings I52 and I53 for power transmission to draw tube II.

Fig. 14 illustrates the use of annular inetlil bellows I90 and' ISI suitably secured to the outer and inner peripheral edges of plates I92 and". as illustrated, establishing the annular air ch'ifnber I94. Telescoping sleeves I and I98 are secured to plates I92 and I93, respectively, and the entire unit is suspended between bearihfl I52 and I53. The balance of the structures in Figs. 13 and 14 are otherwise comparable to the details hereinbefore disclosed in Figs. -1, 2 and 3.

Although the various embodiments have all been devised to be adapted more particularly to continuous axial stock feed through adraw tube and collet, the same could readily be used in other collet and chuck arrangements for grasping individual workor stock pieces from the tooling zone of the lathe.

The description has been confined generally to the disclosures in the drawings which mus trate certain preferred applications of the prim ciples of this invention; However, certain changes and variations are anticipated so that the designs submitted are not to be limited to the exact form, construction or combination of parts shown excepting in so far as shall be tie= term-ined by the breadth and scopeof the am pended claims.

- What I claim is:

1. A fluid operated actuator for imparting rerative endwise movement to a pair of coacting .ro=' tatable members comprising a'first thrust bear= ing connected with one of said members, a sec ond thrust bearing connected with the other of said members, and an expansibleur'iit'disposed between said bearings and surrounding at least one of said members in circumferential spaced relation thereto, whereby said beai'ingscoDpEr ate with said unit to cause said one member to move relatively with respect to said other mem bar when said unit is expanded, said expans'ible unit comprising a plurality of diaphragm stip-' porting plates, connecting means to hold said plates together, a plurality of movable plateshav ing connecting means to impart movement or each movable plate to each adjacent movable plate, and resilient means to'no'rnially maintain said movable plates and diaphragm plates iii nest-ed inoperative relation.

2. A fluid operated actuatorfor iinpaiting rela tive endwise movement to a pair ofcoacting rdt'atable members comprising a first thrust bearing connected with one of said members, a' se 0nd thrustbearing connected with theothez" or said members, and an exparisible uiiit disposed between said bearings and surrounding at least one of said'members in circumferential spaced relation thereto, whereby saidbearings cooperate with said unit to cause said onemember to move relatively with respect to said other member when said-unit is expanded,- said expansible unit coin prising a first setofconnected plates, at secorid set of connected plates adapted for movememri:

ative to said first set of plates, diaphragm members interposed between said two sets of plates to move the same apart, and supporting means connected with one of said sets of plates to hold said expansible unit in self-aligning floating relation between said thrust bearings.

3. A fluid operated actuator for axially shifting a pair of coacting rotatable members relatively to each other comprising a first thrust bearing connected with one of said members, a second thrust bearing connected with the other of said members, and an expansible unit disposed between said bearings and surrounding at least one of said members in circumferential spaced relation thereto, whereby said bearings cooperate with said unit to cause said one member to move relatively with respect to said other memher when said unit is expanded, said expansible unit comprising a plurality of relatively movable plate members, diaphragm elements interposed between said plate members to each move the plate members adjacent thereto apart, and guide means connected between the plate members to maintain the same in aligned positions during the movement of said members relative to each other.

4. A fluid operated actuator for axially shifting a pair of coacting rotatable members relatively to each other comprising a first thrust bearing connected with one of said members, a second thrust bearing connected with the other of said members, and an expansible unit disposed between said bearings and surrounding at least one of said members in circumferential spaced relation thereto, whereby said bearings cooperate with said unit to cause said one member to move relatively with respect to said other member when said unit is expanded, said expansible unit comprising a plurality of relatively movable plates, diaphragms connected between the plates to each react against the plates adjacent thereto, guide means connected between the plates to hold the same aligned during their relative movement with respect to each other, and supporting means connected with certain of said plates to hold the expansible unit in self-aligning floating relation between said thrust bearings.

WILLIAM F. SCI-IROEDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,074,280 Miller Sept. 30, 1913 1,613,090 Fornaca Jan. 4, 1927 2,134,227 Forkardt Oct. 25, 1938 FOREIGN PATENTS Number Country Date 483,499 France July 11, 1917 

